Electronic package whereby an electronic assembly is packaged within an enclosure that is designed to act as a heat pipe

ABSTRACT

An electronic component or assembly that is assembled within a case that is designed to operate as a liquid phase to gas phase heat pipe where said electronic component or assembly is introduced into a liquid or partially liquid partially gaseous environment; whereby said liquid evaporates into a gas absorbing heat energy and transferring it to and through the component&#39;s or assembly&#39;s case. The case will be engineered out of materials that do not contaminate the liquid and electronics with ions and will be engineered to operate in any physical orientation.

CROSS REFERENCE TO RELATED APPLICATIONS

Application No. 60/686,289 Filing Date: Jun. 1, 2005 Confirmation #7771, is a Provisional Patent application for which this application isa non-provisional Utility Patent follow up by the same inventor, RobertJ. Rapp customer #41400.

FEDERAL RESEARCH STATEMENT

Not Applicable, this invention was developed without governmentassistance.

BACKGROUND OF THE INVENTION

Heat pipes have been used to cool electronics for some time, yet heatpipes that use heat to evaporate a liquid into a gas are not containedwithin the same physical case such that the liquid that performs thecooling function is in direct contact with conducive surfaces of anelectronic component or electronic assembly contained within saidenclosure or case. Typically heat pipes are added to electronic devicesafter they have been manufactured into a component or electronicsub-assembly and are not designed into the components case from the verybeginning.

Evaporative heat pipes are available for purchase as separate devicesthat can be added to electronic assemblies to cool them, yet thesedevices do not encase or enclose the electronic components that theycool. These types of heat pipes typically use materials are not wellsuited to enclosing electronic components with exposed conductivesurfaces as they use materials that give up ions easily, as they usematerials such as copper and water. If these materials were used toencase and cool electronics with exposed metallic interconnects theelectronics would be contaminated by ions that would short and/orcorrode metallic contacts contained within. Furthermore since in thesedesigns the liquid is not in direct contact with the electroniccomponents themselves, a fact that limits their performance as heat mustfirst transfer through the components case before they reach heat pipesof this sort.

Other forms of liquid cooling are not small and self contained, as theyrely on circulating a liquid with a pump, or condensing a liquid bycompressing a gas.

Since electronic device densities are increasing rapidly and operatingat ever higher frequencies a new method for cooling electronics that canbe contained within a small package would enable higher powerelectronics to be packaged in highly portable electronic devices thatoperate in configurations of high heat density. Such high heat transfercapabilities are intended to enable electronic devices to operate withincurrent component form factors while minimizing or eliminating the needfor external heat transfer mechanisms that are usually required to coolelectronic components that are typically attached to conventional highheat power electronic devices.

DESCRIPTION OF THE INVENTION

Higher power devices generate vast amount of heat require rapid heattransfer capabilities to keep them functioning optimally. Evaporatingliquids carry a large amount of heat energy away from a point ofevaporation; this type of cooling mechanism is known as a liquid phaseto gas vapor phase heat pipe. The invention describe within is a case orenclosure that surrounds an electronic component, sub-assembly, orassembly that is deigned to operate as a liquid phase to gas vapor phaseheat pipe; where the case of the electronic assembly itself is designedto perform the function said liquid phase to gas vapor phase heat pipe.Here electronic components are in direct contact with a liquid, heatfrom the electronic components evaporates the liquid forming a gasvapor, and the vapor raises carrying heat energy to the case where thisheat energy is conducted into the surrounding environment. Once the gasvapor dissipates thermal energy into the case, it condenses back into aliquid where it rains down or is wicked back down onto the electroniccomponents. The case itself may contain a plurality of chambers wherethe gas vapors can rise into. A plurality of chambers would operate likea group of cooling towers, increasing the surface area in configurationswhere heat can be transferred more efficiently: from the gas vaporthrough the chamber walls and into the external environment.

Furthermore the liquid and the case would be made of materials that willnot contaminate the encased electronic assembly with ions. This is animportant non-obvious benefit of the design. Furthermore the case isdesigned to operate as a heat pipe that encloses the electroniccomponent or assembly is small, self contained, and is designed toperform its function in any orientation. If the electronic component,sub-assembly, or assembly is inverted or turned in any physicalorientation the electronics contained within will remain in contact withthe liquid such that the electronic circuits are optimally cooled. Thecase is designed such that the gas vapor can carry the maximum amount ofthermal energy to the external environment through the case given anyphysical orientation of the case. Furthermore the overall package may bedesigned such that an electronic component packaged within will fitwithin the same form factor as a similar component designed withconventional means, yet provide superior cooling to electronic componentpackaged within.

Another non-obvious benefit of this design is that such an electroniccomponent, sub-assembly, or assembly could be soldered in place onto acircuit board in an oven, even if the electronic components inside wereoriginally soldered with similar materials & temperatures. In this casethe electronic assembly contained within the heat pipe would beprotected from the external heat of the oven. The solder holdingelectronic components in place on the inside of the heat pipe would becooled by the fluid contained within the heat pipe long enough for thecomponent to be soldered to an external circuit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows an electronic assembly whereby a case/enclosure 1A containsa conventional electronic assembly/sub-assembly 3A, a liquid 2A, and agas vapor that forms a liquid phase to gas phase heat pipe. Also shownare pads 5A by which the overall electronic assembly may be soldered toa printed circuit board by standard assembly processes.

FIG. 2 shows an electronic assembly whereby a case/enclosure 1B containsa conventional electronic assembly/sub-assembly 3B, a liquid 2B, and agas vapor that forms a liquid phase to gas phase heat pipe. Also shownare pads 5B by which the overall electronic assembly may be soldered toa printed circuit board by standard assembly processes. Furthermorecontains a plurality of chambers/towers 6 that are designed to optimizethe cooling of the electronic assembly contained within in any physicalorientation.

FIG. 3 shows an electronic assembly whereby a case/enclosure 1B containsa conventional electronic assembly/sub-assembly 3C, a liquid 2C, and agas vapor that forms a liquid phase to gas phase heat pipe. Also shownare pins 5C by which the overall electronic assembly may be soldered toa printed circuit board by standard assembly processes. Furthermorecontains a plurality of chambers/towers 7 that are designed to optimizethe cooling of the electronic assembly contained within in any physicalorientation.

1. An enclosure that contains an electronic assembly and a liquid thatis designed to operate as a heat pipe for cooling electronics containedwithin.
 2. Claim 1 where said enclosure contains some portion of liquidand some portion of gas such that said enclosure operates as a liquidphase to a vapor phase heat pipe where said liquid evaporates into a gasvapor into a gas vapor transfers heat and condenses back into a liquid.3. Claim 2 where said enclosure maintains some potion of said liquid incontact with said electronic assembly despite the physical orientationof said electronic assembly.
 4. Claim 3 where said enclosure includes aplurality of chambers where said gas vapor can move, where said chambersare designed to maximize the surface area of said enclosure such thatthermal energy is moved from said gas vapor through said enclosure moreefficiently.
 5. Claim 4 where said chambers are comprised of cylindersthat form cooling towers and said enclosure is comprise of a materialthat does not freely emit ions.
 6. Claim 3 where said electronicassembly consists of at least one integrated circuit.
 7. Claim 6 wheresaid integrated circuits are wire bonded.
 8. Claim 6 where saidintegrated circuits are soldered.
 9. Claim 6 where said integratedcircuits are attached by conductive epoxy.
 10. Claim 6 where saidintegrated circuits are attached by other means.
 11. Claim 6 where saidintegrated circuits form an electronic sub-assembly.
 12. Claim 3 wheresaid electronic assembly and case are contained within the form factorof an electronic device that is packaged by means that do not use saidliquid phase to gas vapor phase heat pipe.
 13. Claim 4 where saidelectronic assembly and case are contained within the form factor of anelectronic device that is packaged by means that do not use said liquidphase to gas vapor phase heat pipe.
 14. Claim 5 where said electronicassembly and case are contained within the form factor of an electronicdevice that is packaged by means that do not use said liquid phase togas vapor phase heat pipe.